Appease jschuh@ by adding a setting to move 'plugin' to blockable mixed content.

Source/web/WebSettingsImpl.cpp

Index: Source/web/WebSettingsImpl.cpp
diff --git a/Source/web/WebSettingsImpl.cpp b/Source/web/WebSettingsImpl.cpp
index 89b95d3c06635295b47cd02f07b79fd456acde46..adf44832bf3a147a239abcebefbfb89c2b4b3d80 100644
--- a/Source/web/WebSettingsImpl.cpp
+++ b/Source/web/WebSettingsImpl.cpp
@@ -614,6 +614,11 @@ void WebSettingsImpl::setStrictMixedContentChecking(bool enabled)
     m_settings->setStrictMixedContentChecking(enabled);
 }
 
+void WebSettingsImpl::setStrictMixedContentCheckingForPlugin(bool enabled)
+{
+    m_settings->setStrictMixedContentCheckingForPlugin(enabled);
+}
+
 void WebSettingsImpl::setStrictPowerfulFeatureRestrictions(bool enabled)
 {
     m_settings->setStrictPowerfulFeatureRestrictions(enabled);